The Transport Layer Security (TLS) protocol includes a session ticket extension that allows a secure communication session between two computers to resume with an abbreviated handshake based on a pre-known state for a limited time. The session ticket extension offloads the caching of the application server session state to the application client. An intermediary network device may be included in the path of a TLS/Secure Sockets Layer (SSL) connection to provide additional services, such as a firewall, intrusion detection/prevention, and/or load balancing.
To participate in a session between an endpoint client and an endpoint server secured with the TLS security protocol, an intermediary device will typically interpose itself and create two separate SSL/TLS sessions. The intermediary device creates one TLS session between the application client and a proxy server at the intermediary device. A proxy client at the intermediary device initiates the second TLS session with the application server.
The Internet Engineering Task Force (IETF) Request For Comments (RFC) 5077 describes TLS session ticket extension specifications over the TLS protocol. RFC 5077 describes an application server sending a new session ticket to the application client before the Change Cipher Spec message. This ticket is opaque to the application client and is used to establish SSL/TLS connections of the same session with the application server using an abbreviated handshake.